If you can't think of any better way to balance one of these beasts you can always do this:
$\displaystyle aH_2S + bKMnO_4 + cH_2SO_4 \to dK_2SO_4 + eS_8 + fMnSO_4 + gH_2O$
where the a, ..., g are your balancing coefficients.

Now work through each element on each side of the reaction:
For H:
2a + 2c = 2g